Most of my Readers are aware that the NIH budget allocation from Congress plays a big role in our careers and how they have unfolded over years or even decades.

One of the touchstone events is the "doubling interval" in which the Congress committed to double the size of the NIH budget over the course of 10 years. This resulted in large year-over-year increases from 1994 to 2003 after which the NIH budget was essentially flatlined for the next dozen years. This is in current dollars so, as we've discussed on this blog, inflation means that the NIH budget shrunk in purchasing power over the post-doubling interval. ARRA stimulus funding in Fiscal Years 2009 and 2010 were mere blips, which alleviated acute pain but did little for the longer term issues.

One interesting thing about being me is that my NIH geekery has limits and I don't always appreciate everything fully the first time I see it. Sometimes it is because I am, like many of us, blinded by a sort of confirmation bias. I am by no means alone in seeing confirmation of my positions in data and statistics about the NIH that others view entirely differently. Sometimes it is because an earlier trend gets fixed in my minds and I don't always see the way five or ten additional years worth of data may change my thinking.

One of these issues is related to the data showing the production of PhDs each year by US domestic degree granting institutions. Our good blog friend Michael Hendricks posted this graph on the Twitters today. He, as I usually do, interprets this to show the evils of the doubling interval when it comes to regulating the size of the workforce. The first half of the doubling interval did indeed correlate with a steep increase in the rate of annual biomedical PhD generation without a similar trend for doctoral production in other areas. I typically use this steep increase in PhD production as part of my argument that our current stress in staying funded is related to too many mouths at the trough. We generated all these PhDs during the late 90s onward and gee, shocker, lots of these people want faculty level jobs competing for a fixed amount of NIH funding. Retirement and death of the existing pool of NIH PIs has not kept pace with this production, from what I can tell.

My usual eye tends to skip over a couple of key facts. The steep increase in PhD production started several years before the doubling even started. It was in full swing during a time just prior to the doubling passing Congress when the faculty were crying loudly about how horrible the NIH grant getting had become. I know because I was in graduate school in there somewhere.

The year-over-year PhD production actually stabilized during the latter half of the doubling interval. This was followed after the NIH budget flatlined by another increase in the rate of year-over-year PhD production!

So I think Michael Hendricks' current view, and my prior view, on the meaning of the PhD production numbers and how it relates to major changes in the NIH budget allocation cannot be true.

Sustained increase in the NIH budget actually produced stability in PhD numbers. It was the stressful times in which NIH grant getting was perceived to be ruinous and terrible that led to increased numbers of PhDs being generated by the US doctoral institutions.

There are probably many reasons for this relationship. I would not be surprised in the least if bad general economic times led more people to want to go to grad school and booming economic times led to fewer. These general trends are very likely related to the willingness of the Congress to give NIH more or less money.

But I would also not be surprised in the least if stressful grant funding conditions led the professors who participate in graduate training to be even more fond of this source of cut rate labor than they are in flush times.

As someone working at a PUI I wonder if the high numbers of PhD's don't have a more organic source as well. I'm thinking that the increasingly goal-oriented culture among young people going to college and those advising them (while not unreasonable given what people thought they knew about the importance of higher Ed to success) likely contributed to this increase as well as NIH funding situation.

Starting in the 90's and 00's the proportion of undergraduates coming in as pre-medical / biology majors has increased steadily, and still increases (and usually without any increase in support from institutions for those of us that actually have to teach and advise these people). As we all know the vast majority of these people will not go to Medical school. A proportion of them will go into other medical careers of course, yet a good chunk will choose graduate school as they had the chance to catch the research bug, and most of those will choose biomedical graduate school specifically. Thus the supply of undergraduates seeking a PhD (and also the quality of those candidates) must surely have increased during this period.

Naturally where the NIH funding comes in is that without some sort of funding, those graduate students wouldn't have a place to go. But graduate programs have a way of finding spots for talented students I think.

I tend to blame the economy to explain things when possible. For example, it has not escaped my notice that unemployment is down and this is when #GRExit becomes a thing. Although it's a trend I generally applaud, it might be an easier sell to universities when applications are a bit down compared to when they are a bit up.

But I don't see anything about 1998 that makes it the inflection point for basic biomed PhDs. Mostly, you'd expect the economy to cause in increase in all degrees (with perhaps a 4-7 year lag). I do think it's worth understanding the *other* inflection point, the one in MDs graduated that proceeds the PhD thing. Do med schools usually do a cohort or two of MDs before adding PhD capacity as they rev up education?

There's a similar phenomenon with the (admittedly pretty poor estimate of) number of postdocs, that it doesn't follow NIH funding patterns. Makes sense, because Ginther has data in the post-postdoc earnings paper showing 80% of U.S. biomed PhDs do a postdoc, and that has been the case since the 80s, so the grad and postdoc numbers seem to follow a similar but largely NIH-independent pattern - thanks for pointing this out.

I don't know where this data is but it would be interesting to look at when/how institutions have pushed for more graduate students/whether those incentives shifted over time, because at the moment this is a metric they are competing on. It's messy, because for example with the postdoc salaries/FLSA, about half of the schools were planning to increase graduate programs to compensate for the expected shortfall in labor, and the other half were saying there wasn't any funding to do that. It would be interesting to focus on the big PhD factories to see whether their numbers all changed in response to some similar policy/incentive.

At my institution, graduate students can be funded on TAs if grant funding lapses. This strongly incentivizes taking on graduate students during lean times, when overlapping grants and "easy" renewals are more rare.

Does anyone know what fraction of biomedical grad students in the US are funded by NIH money? And how are 80% of them doing post docs when NIH funding is tight? Grad students are often funded on TAs but I don’t know of major alternative for post docs.

"But I don't see anything about 1998 that makes it the inflection point for basic biomed PhDs."

Perhaps the dot-com era (1995-2000). I was in grad school at the time and quite a few of my contemporaries dropped out of grad school (and I'd imagine plenty never applied) because you could get an $75K job just knowing basic HTML and/or a bit of Perl with no need for an actual computer science degree.

> Who actually sets the enrollment targets for graduate programs? Is that done at the departmental level, or higher up?

Where I am at (big public university), the graduate enrollment admissions is handled entirely within the department. We could choose to admit 0 or 100 students. There is some quality oversight higher up. If you want to admit a student with a poor undergrad GPA, you need to justify it. (We also have zero say in undergraduate enrollment.)

However, there are many many incentives (meaning money) offered by the School's Dean and the University's President to increase graduate enrollment. It's also clear that if your graduate enrollment drops, other internal funding controlled by the dean will drop.

"The year-over-year PhD production actually stabilized during the latter half of the doubling interval. This was followed after the NIH budget flatlined by another increase in the rate of year-over-year PhD production!"

My hunch has been that the lag between NIH funding and PhD graduation rates is simply due to the considerable amount of time it takes to expand a department and output new graduates.

Thus, the NIH budget starts increasing in 1999, but it takes a couple years to expand departments and hire new faculty, which then take on students that graduate starting around 2006.

As the NIH budget peaks, continued growth requires universities to build new facilities, which adds a few years to this lag. Following the NIH budget peak in 2003, universities were still deciding to build new research buildings, which might be completed and filled with new departments and graduate programs by 2006. This contributes to continued growth in PhD graduation rates through 2013.

That's my half-formed hypothesis at least, though it says nothing about the increase in PhDs starting in the late 1980s. Is there good data about numbers of NIH-funded PIs, new construction of research facilities, etc?